A PBS file is a presets file used by Corel PaintShop Pro, a program used for editing images and digital photos. It contains a collection of brush strokes used by the Brush tool in PaintShop Pro. PBS files include shape, texture, dynamics, and other data for each brush style.

PaintShop Pro allows you to choose from different brush styles when using its brush tool on the canvas. The different presets for the brushes are stored in the PBS file and are used for simulating the texture of various types of brushes. Although you use the brush presets through the program's interface, you most likely will not come across an actual PBS file unless you download or receive new brushes from a site or another PaintShop Pro user.